Hey there nice work..
To make lights less lumpy...I am assuming you are talking about the background...use the lasso or mask tools to mask or lasso out a section...then use a gradient that you want. Or make a selection, and hit ALT-Backspace to fill it with the foreground color. you can even make sure when you are painting the lights, to paint them in the direction that the light is going...then any little inconsistencies look like streaming light...and not blotches. If you are using a wacom...you can turn off the opacity to keep the brush even...and use the opacity in the options box for glaze effects.